Transmission shift selector assembly

ABSTRACT

The present disclosure relates to various shift selector assemblies having a shift gate with a plurality of indentations corresponding to transmission shift selections. At least one of the indentations is configured to have a flexible depth so as to selectively restrict and accept a pawl pin, thereby mitigating shift position overshoot.

CROSS REFERENCE TO RELATED APPLICATIONS

The present patent application claims the benefit of and is a divisionalof U.S. patent application Ser. No. 12/916,466, filed Oct. 29, 2010,which is incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to transmission shifter assembliesconfigured to mitigate shift-position overshoot.

BACKGROUND

Conventional vehicles with automatic transmissions have a transmissionshifter assembly that translates user commands for transmissionoperation to the transmission. In modern vehicles, the shifters can bemechanically or electrically controlled. With mechanical systems a usermoves a shift lever to a position that correlates with a transmissionmode of operation (e.g., park (“P”), reverse (“R”), neutral (“N”), drive(“D”) and low drive (“L/M”)). The shifter assembly includes a shift gatewith indentations that correspond to each lever position andtransmission mode of operation. The user presses a button on the shiftlever that releases a pawl-to-gate connection, the lever is free to movewith respect to the shift gate and the user releases the button once theshift lever is in the intended position to lock the lever in place.

Overshoot of an intended shift position can occur when the user movesthe shift lever too fast or too aggressively. Overshoot depends on thespeed of the shift, how aggressive the user is when shifting, and howthe release button is pressed. One U.S. Patent Publication No.2009/0272216 titled, “Shift Selector Apparatus” teaches a shift assemblythat manages shift overshoot by designing a shift path with a wideintermediate spatial break (or “bump zone”) that divides and first andsecond shift zone. This arrangement, however, requires significantlymore space for the shifter assembly.

Other solutions involve creating an artificial feel of the shift eventthrough changes to the shifter lever. Another published patentapplication includes a damper that provides resistance to movement ofthe lever in order to counterbalance faster movement of the shiftlever—Japanese Patent Application Publication No. JP 03223566 titled“Shift Indicating Device for Automatic Transmission.” This designinvolves spring biasing the shift lever to resolve overshoot which canbe complicated, require more parts and greater durability thresholds forthose parts. Overshoot is more simply managed in the shift gate than inthe shift lever as doing so does not compromise shift lever performanceor feel.

Therefore, it is desirable to have a more compact, simpler shifterassembly that is configured to mitigate overshoot in the shift path inat least one direction.

SUMMARY

The present invention may address one or more of the above-mentionedissues. Other features and/or advantages may become apparent from thedescription which follows.

Certain embodiments of the present invention relate to a transmissionshift gate assembly, including: a plurality of indentationscorresponding to shift selections and a spring-loaded member included inan indentation configured to have a flexible depth so as to selectivelyrestrict and accept a pawl pin. The spring-loaded member is aretractable plunger. At least one of the indentations is configured tohave a flexible depth so as to selectively restrict and accept a pawlpin.

Another embodiment of the present invention relates to a transmissionshift selector, including: a base; a shift lever pivotally coupled tothe base; a shift gate having a plurality of indentations correspondingto a shift selection; and a pawl pin coupled to the shift lever, matablewith the indentations; and a spring-loaded member included in theindentation configured to have a flexible dept. The spring-loaded memberis a retractable plunger. At least one of the indentations is configuredto have a flexible depth so as to selectively restrict and accept thepawl pin.

Another exemplary embodiment of the present invention relates to amethod of mitigating overshoot in a transmission shift selector, themethod includes: forming a shift gate with a plurality of indentationsthat correspond to different shift selections; and altering the depth ofat least one indentation in the shift gate between a restricted positionand a receptive position. The restricted position mitigates overshoot ina first direction and the receptive position mitigates overshoot in asecond direction.

One advantage of the present teachings is that they minimize theopportunity for the driver to overshoot a shift position when shiftingin either a forward or a rearward direction.

Another advantage of the present teachings is that more packaging spaceis available in the vehicle since the shift gate and shift assembly arerelatively compact while still mitigating shift position overshoot.

In the following description, certain aspects and embodiments willbecome evident. It should be understood that the invention, in itsbroadest sense, could be practiced without having one or more featuresof these aspects and embodiments. It should be understood that theseaspects and embodiments are merely exemplary and explanatory and are notrestrictive of the invention.

The invention will be explained in greater detail below by way ofexample with reference to the figures, in which the same referencesnumbers are used in the figures for identical or essentially identicalelements. The above features and advantages and other features andadvantages of the present invention are readily apparent from thefollowing detailed description of the best modes for carrying out theinvention when taken in connection with the accompanying drawings. Inthe figures:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a perspective view of a vehicle interior having anexemplary floor-mounted shift selector assembly therein.

FIG. 2 is a partial cross-sectional view of the shifter assembly of FIG.1.

FIG. 3 is a partial cross-sectional view of the shifter assembly of FIG.2 with a shift gate indentation in a restriction depth.

FIG. 4 is a partial cross-sectional view of the shifter assembly of FIG.2 with the shift gate indentation in a reception depth.

FIG. 5 is a cross-sectional view of another exemplary shifter assemblywith a shift gate indentation arm in a restriction depth.

FIG. 6 is a cross-sectional view of another exemplary shifter assemblywith the shift gate indentation arm of FIG. 5 in a reception depth.

FIG. 7 is a cross-sectional view of another exemplary shifter assemblywith a shift gate indentation arm in a restriction depth.

FIG. 8 is a cross-sectional view of another exemplary shifter assemblywith the shift gate indentation arm of FIG. 7 in a reception depth.

Although the following detailed description makes reference toillustrative embodiments, many alternatives, modifications, andvariations thereof will be apparent to those skilled in the art.Accordingly, it is intended that the claimed subject matter be viewedbroadly.

DETAILED DESCRIPTION

Referring to the drawings wherein like characters represent the same orcorresponding parts throughout the several views there are shownexemplary transmission shift selector assemblies. Shifter assembliesenable the driver to control the mode of transmission operation. Shifterincludes a user input device (e.g., a shifter lever) that is connectedto various electrical and mechanical transmission components positionedbelow the input device. The shift selector assemblies are beneficial inthat a shift gate has a shift path with at least one flexibleindentation, thereby reducing shift position overshoot in one or moredirections. One common user issue is unintended selection of a shiftposition (e.g., low/manual/3/2/1) when shifting from another shiftposition (e.g., park to drive). The shift selectors are compatible withmechanical and electro-mechanical shift assemblies used with eitherautomatic or manual transmissions. The transmission can be anyconventional transmission such as, for example, a continuously variableor an electrically variable transmission. Moreover, while theillustrated embodiments relate to floor-mounted shift selectors,steering column mounted shift selectors can be used with the presentteachings.

Referring now to FIG. 1, there is shown therein a vehicle interior 10having a shift selector assembly 20 mounted to a floor console 30. Thevehicle interior 10 includes an instrument panel 40. The instrumentpanel 40 spans across the front end of a vehicle; the panel 40 includesa steering wheel 50 and storage compartment 60. The floor console 30 isattached to a floor pan of the vehicle (e.g., 120 as shown in FIG. 2).

In a front section of the floor console the shifter selector assembly 20is mounted to the floor console 30. Shift selector assembly 20 includesa shift lever 70 to enable a vehicle driver to change the transmissionmode of operation. The front section of the console 30 includes a finishpanel 80 through which the shifter lever 70 extends. In this embodiment,shifter assembly 20 is for an automatic transmission. At the exposedend, shift lever 70 includes a shift knob 90. The shifter assembly 20includes a housing 100 attached to the shift lever 70. In the shownembodiment, housing 100 is a boot composed of a fluid resistantmaterial. Housing 100 is attached to the console 30 through a retainerring 110 positioned between the housing 100 and the console 30. Shiftselector is capable of selective several modes of operation for thevehicle transmission as discussed herein below.

FIG. 2 illustrates a partial cross-sectional view of the shift selectorassembly 20 of FIG. 1. The shifter assembly 20 includes the shift lever70 through which a user indicates instruction for transmission mode ofoperation. Shift lever 70 is pivotally connected to the floor pan 120 orbase of the assembly and is configured to rotate about point 130. Thelever 70 includes knob 90 at the top that has a release button 140 thatthe user can press to drive the position of a lock or pawl pin 150. Thepawl pin 150 is coupled to the shift lever 70 and configured to rotatewith the lever. Pawl pin 150 is matable with a number of shift positionindentations (or detents) in a shift gate 160. When the pawl pin 150engages an indentation the pawl locks the shifter lever into therelative shift position.

A five-position automatic transmission shift gate 160 is shown in FIG.2. The shift gate includes a shift path defined by five indentations170, 180, 190, 200 and 210. From the front portion of the shift gate tothe rear are the following shift positions:park-reverse-neutral-drive-low/manual/sport (or “P-R-N-D-L/M/S”). Eachof the indentations 170, 180, 190, 200 and 210 corresponds to a shiftselection. Each indentation 170, 180, 190, 200 and 210 also defines adepth or relative distance from an inner surface 220 of the shift gateto an outer surface 230 of the shift gate. Depth is a radial dimensionand measured in a direction relative to the shift lever position whenpositioned at the respective indentation.

In the illustrated embodiment, when overshoot occurs the intended shiftposition is drive or “D” but the shift lever 70 lands in the low manualposition or “L/M/S.” Typically a driver would have to retrace theirsteps and shift forward to remedy the overshoot. Overshoot results froma very small difference between the depth of two or moreindentations—e.g., the drive front wall at indentation 190 andlow/manual front wall at indentation 200, as shown in FIG. 2. In thisembodiment, there is overshoot potential when the user starts fromindentation 170 and shifts to indentation 200 (or park to drive).

The illustrated embodiment of FIG. 2 addresses overshoot by adding aspring-loaded member, in this case a retractable plunger 240, inindentation 210 or the L/M/S position. The plunger 240 extends from therear of the L/M/S indentation 210 to the rear of the drive indentation200. Surface 250 acts as a wall to prevent overshoot from P-to-D whenthe plunger 240 is in the restriction position (as shown in FIG. 2).Surface 260 defines the depth of the indentation 210. Since surface 260is movable with respect to the floor pan 120, indentation 210 has aflexible depth, as comparatively shown in FIGS. 3 and 4. Surface 260engages the pawl pin 150 when the plunger 240 is retracted. The plunger240 is spring-loaded and biased toward a downward position or restrictedposition when the spring 270 is uncompressed.

FIGS. 3 and 4 show three indentations in the shift gate assembly withindentation 210 defining a restriction depth and reception depth,respectively. Plunger 240 is retractable, when spring 270 is compressedsurface 260 on plunger is positioned at a greater depth than when in therestricted position, as shown in FIG. 3. The restriction depth is lessthan the reception depth—i.e., when the spring 270 is compressed. In therestricted position plunger 240 has a depth that is less than the depthof indentation 190 or indentation 200. Since indentation 210 isshallower than indentations 190 and 200 it is more difficult toovershoot indentation 200 when shifting rearward. When pawl 150 isengaged with the indentation 210, the depth of indentation 210 is stillless than the depth of indentation 190. The difference in depth betweenindentations 190 and 210, delta d, is within a predetermined range. Therange is ergonomically derived so that the difference in depth betweenindentations 190 and 210 is not so great that the user fails to detectindentation 200 when shifting in a forward direction. In thisembodiment, the depth of indentation 210 is within +/−25% of the depthof indentation 190. An exemplary depth for indentation 190 is 7millimeters and an exemplary depth for indentation 210 in the receptionposition is 6 millimeters. In other embodiments, different shiftpositions are assigned to the shift gate indentations. Shift gate 160can include more or less than five shift positions and overshoot can besimilarly mitigated with respect to any one of the shift positions.

Shift gate 160 includes a chamfered edge 280 between indentations 200and 210 to further guide pawl pin 150 into engagement with indentation200 during forward travel of the shift lever 70 from indentation 210. Inthis embodiment, chamfered edge 280 is approximately 1 millimeter inlength or 45 degrees.

A reinforcement surface 290 is also included in the gate 160, of FIGS. 3and 4, at indentation 210. Reinforcement surface 290 is extended fromthe inner surface 220 of shift gate 160 to give greater structuralrigidity to the gate during repetitive shifting. In this embodiment, theshift gate 160 and reinforcement surface 290 are composed of the samematerial—a hard plastic. Shift gate 160 is molded in an injectionmolding process. The plunger 240 is secured to the shift gate 160 in asecondary process with a fastener (e.g., a rivet, screw, weld or glue).Shift gate 160 can also be formed from a solid plastic or othermaterial. In other embodiments, reinforcement surface 290 is composed ofa different material than shift gate 160 (e.g., an epoxy, metal orrubber material).

Referring now to FIG. 5 there is shown therein a partial cross-sectionalview of another shift selector assembly 300. The shifter assembly 300includes a shift lever 310 through which a user indicates instructionfor transmission mode of operation. Shift lever 310 is pivotallyconnected to the floor pan or base of the assembly. The lever 310includes a knob with release button that drives the position of a pawlpin 320. Pawl pin 320 is matable with a number of shift positionindentations (or detents) in the shift gate.

An automatic transmission shift gate 330 is partially shown in FIG. 5.The shift gate 330 includes a shift path defined by indentations 340,350, 360 and 370. Each of the indentations 340, 350, 360 and 370corresponds to a shift selection and each indentation also defines adepth or relative distance from an inner surface of the shift gate 380to an outer surface of the shift gate 390.

A spring-loaded member 400 is added in indentation 370 as shown in FIG.5. The spring-loaded member 400 is an arm configured to pivot withrespect to the shift gate 330. The arm 400 is spring-mounted to theshift gate 330 by a rotational spring 410. Surface 420 acts as a wall toprevent overshoot of indentation 360 when the arm 400 is in therestriction position (as shown in FIG. 5). Surface 430 defines the depthof the indentation 370. Since surface 430 is movable with respect to thefloor pan or shift gate 300, indentation 370 has a flexible depth.Surface 430 engages the pawl pin 320 when the arm 400 is rotated upwardand spring 410 is compressed. The arm 400 is biased toward a downwardposition or restricted position when the spring 410 is uncompressed.

FIGS. 5 and 6 show indentation defining a restriction depth andreception depth, respectively. Arm 400 is retractable, when spring 410is compressed surface 430 on arm is positioned at a greater depth thanwhen in the restricted position. The restriction depth is less than thereception depth—i.e., when the spring 410 is compressed. In therestricted position, as shown in FIG. 5, arm 400 has a depth that isless than the depth of indentation 360 or indentation 350. Sinceindentation 370 is shallower than indentations 350 and 360 it is moredifficult to overshoot indentation 360. When pawl 320 is engaged withthe indentation 370, the depth of indentation 370 is still less than thedepth of indentation 350. The difference in depth between indentations370 and 350 is within a predetermined range e.g., within +/−40% of thedepth of indentation 350. An exemplary depth for indentation 350 is 9millimeters and an exemplary depth for indentation 370 in the receptionposition is 7 millimeters.

Referring now to FIG. 7 there is shown therein a partial cross-sectionalview of another shift selector assembly shift gate 500. A pawl pin 510is matable with a number of shift position indentations (or detents) inthe shift gate. The transmission shift gate 500 is partially shown inFIG. 7. The shift gate 500 includes a shift path defined by indentations520, 530, 540 and 550. Each of the indentations 520, 530, 540 and 550corresponds to a shift selection and each indentation also defines adepth or relative distance from an inner surface of the shift gate 560to an outer surface of the shift gate 570.

A spring-loaded member 580 is added in indentation 550 as shown in FIG.7. The spring-loaded member 580 is an arm configured to pivot withrespect to the top of shift gate 500. The arm 580 is spring-mounted tothe shift gate 500 by a rotational spring 590. Surface 600 acts as awall to prevent overshoot of indentation 540 when the arm 580 is in therestriction position (as shown in FIG. 7). Surface 600 also at leastpartially defines the depth of the indentation 550. Since surface 600 ismovable with respect to the floor pan or shift gate 500, indentation 550has a flexible depth. Surface 600 engages the pawl pin when the arm 580is rotated rearward and spring 590 is compressed. The arm 580 is biasedtoward a forward position or restricted position when the spring 590 isuncompressed.

FIGS. 7 and 8 show indentation 550 defining a restriction depth andreception depth, respectively. Arm 580 is retractable, when spring 590is compressed surface 600 on arm is positioned at a greater depth thanwhen in the restricted position. The restriction depth is less than thereception depth—i.e., when the spring 590 is compressed. In therestricted position arm 580 has a depth that is less than the depth ofindentation 530 or indentation 540. Since indentation 550 is shallowerthan indentations 530 and 540 it is more difficult to overshootindentation 540. When pawl 510 is engaged with the indentation 550, thedepth of indentation 550 is still less than the depth of indentation530. The difference in depth between indentations 530 and 550 is withina predetermined range e.g., within +/−10% of the depth of indentation530. An exemplary depth for indentation 530 is 4 millimeters and anexemplary depth for indentation 550 in the reception position is 3.6millimeters.

The present teachings enable use of a method of mitigating overshoot ina transmission shift selector. The method includes the steps of: forminga shift gate with a plurality of indentations that correspond todifferent shift selections; and altering the depth of at least oneindentation in the shift gate between a restricted position and areceptive position (e.g., as shown and discussed with respect to FIGS. 2through 8). The restricted position (or depth) of the indentationmitigates overshoot in a first direction and the receptive position (ordepth) mitigates overshoot in a second direction. For example, as taughtwith respect to FIGS. 2-4, the restricted position of the indentation210 mitigates overshoot of indentation 200 in a first direction and thereceptive position (or depth) of indentation 210 mitigates overshoot ofindentation 200 in a second direction. The flexible depth of indentation210 mitigates position overshoot in multiple directions. Altering thedepth of the indentation can include spring-mounting a member withrespect to the shift gate (e.g., as shown with respect to the plunger240 and rotational arms 400 and 580, as shown in FIGS. 5-6 and 7-8,respectively). Shift gate can include other means for having a flexibledepth including having a malleable material included therein (e.g., arubber or foam); a leaf spring incorporated therein; a pneumatic damper;or a solenoid. The method also includes chamfering the edge of at leastone indentation in the shift gate to guide a pawl pin with respect tothat indentation (as shown in FIGS. 3-4).

It will be apparent to those skilled in the art that variousmodifications and variations can be made to the methodologies of thepresent invention without departing from the scope its teachings. Otherembodiments of the invention will be apparent to those skilled in theart from consideration of the specification and practice of theteachings disclosed herein. It is intended that the specification andexamples be considered as exemplary only.

While the best modes for carrying out the invention have been describedin detail, those familiar with the art to which this invention relateswill recognize various alternative designs and embodiments forpracticing the invention within the scope of the appended claims.

1. A method of mitigating overshoot in a transmission shift selector, comprising: forming a shift gate with a plurality of indentations that correspond to different shift selections; and altering the depth of at least one indentation in the shift gate between a restricted position and a receptive position; wherein the restricted position mitigates overshoot in a first direction and wherein the receptive position mitigates overshoot in a second direction.
 2. The method of claim 1, wherein the altering the depth of the indentation includes spring-mounting a member with respect to the shift gate.
 3. The method of claim 1, further comprising: chamfering the edge of at least one indentation in the shift gate to guide a pawl pin with respect to that indentation.
 4. A method of mitigating overshoot in a transmission shift selector, comprising: moving a spring-loaded retractable plunger relative to one indentation of a shiftgate having multiple indentations of different radial distance from a pivot, producing a greater radial distance from the pivot that admits a pawl pin into the one indentation; moving the plunger relative to the one indentation, producing a lesser radial distance from the pivot that restricts the pawl pin from the one indentation.
 5. The method of claim 4 further comprising: moving the shift selector between a first indentation of the shiftgate corresponding to a first shift selection, a second indentation of the shiftgate corresponding to a second shift selection positioned aft of the first indentation, and the one indentation positioned aft of the second shift selection.
 6. The method of claim 5 wherein the second shift selection position corresponds to a Drive selection and the one indentation corresponds to a Manual selection.
 7. The method of claim 4 wherein moving the plunger to producing a greater radial distance includes moving the plunger against a bias of a spring attached to the plunger 